scholarly journals Particle Concentration Comparison of Radiator and Floor Heating Systems under Zero Air Change Rate Condition

2021 ◽  
Vol 21 (11) ◽  
pp. 210148
Author(s):  
Mustafa Mutlu
2019 ◽  
Vol 111 ◽  
pp. 02037
Author(s):  
Mustafa Mutlu

Dispersion of airborne particles in the office and residential areas should be well known as these particles in an enclosed volume has a significant effect on human health. In this study, the effect of the floor heating system, which is often preferred by end users due to the energy efficiency of low heating systems, on particle distribution in a room was investigated numerically. It is essential to examine the floor heating having a significant place among low heating systems, concerning particle dispersion. In enclose volumes, ambient air should be replaced with fresh air that is supplied from outdoor in order to ensure indoor air quality. However, the ideal air change rates may not be met for daily use, even in some cases air change rates might be zero. Therefore, in this study absence of air change were assumed, and after temperature and velocity distributions were determined, five different sized particles were tracked by using Eulerian-Lagrangian model. Additionally, three heating capacities (35 W/m2 41.25 W/m2 and 47 W/m2) of the floor heating system were investigated. In this study, where computational fluid dynamics were used, the effect of drag, lift, thermophoretic and Brownian forces were considered. It was found that particles were settled on walls and ceiling due to zero air change rate, and particle concentration rises in the lower part of the wall as particle diameter increases.


Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1321
Author(s):  
Yu-Jin Hwang ◽  
Jae-Weon Jeong

The objective of this research is to establish an appropriate operating strategy for a radiant floor heating system that additionally has an air source heat pump for providing convective air heating separately, leading to heating energy saving and thermal comfort in residential buildings. To determine the appropriate optimal operating ratio of each system taking charge of combined heating systems, the energy consumption of the entire system was drawn, and the adaptive floor surface temperature was reviewed based on international standards and literature on thermal comfort. For processing heating loads with radiant floor heating and air source heating systems, the heating capacity of radiant floor heating by 1 °C variation in floor temperature was calculated, and the remaining heating load was handled by the heating capacity of the convective air heating heat pump. Consequently, when the floor temperature was 25 °C, all heating loads were removed by radiant floor heating only. When handling all heating loads with the heat pump, 59.2% less energy was used compared with radiant floor heating only. Considering the local discomfort of the soles of the feet, the floor temperature is expected to be suitable at 22–23 °C, and 31.5–37.6% energy saving compared with those of radiant floor heating alone were confirmed.


Buildings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 259
Author(s):  
Ádám László Katona ◽  
István Ervin Háber ◽  
István Kistelegdi

A huge portion of energy consumption in buildings comes from heating, ventilation, and air conditioning. Numerous previous works assessed the potential of natural ventilation compared to mechanical ventilation and proved their justification on the field. Nevertheless, it is a major difficulty to collect enough information from the literature to make decisions between different natural ventilation solutions with a given situation and boundary conditions. The current study tests the passive air conduction system (PACS) variations in the design phase of a medium-sized new winery’s cellar and production hall in Villány, Hungary. A computational fluid dynamics simulation based comparative analysis enabled to determine the differences in updraft (UD) and downdraught (DD) PACS, whereby the latter was found to be more efficient. While the DD PACS performed an air change range of 1.02 h−1 to 5.98 h−1, the UD PACS delivered −0.25 h−1 to 12.82 h−1 air change rate. The ventilation performance of the DD version possessed lower amplitudes, but the distribution was more balanced under different wind incident angles, thus this version was chosen for construction. It could be concluded that the DD PACS provides a more general applicability for natural ventilation in moderate climates and in small to medium scale industry hall domains with one in- and one outlet.


Measurement ◽  
2018 ◽  
Vol 124 ◽  
pp. 539-548 ◽  
Author(s):  
Marcel Macarulla ◽  
Miquel Casals ◽  
Núria Forcada ◽  
Marta Gangolells ◽  
Alberto Giretti

Author(s):  
Iveta Bullová ◽  
Peter Kapalo ◽  
Dušan Katunský

Air change rate is an important parameter for quantification of ventilation heat losses and also affects the indoor climate of buildings. Indoor air quality is significantly associated with ventilation. If air change isn't sufficient, trapped allergens, pollutants and irritants can degrade the indoor air quality and affect the well-being of a building's occupants. Many studies on ventilation and health have concluded that lower air change rates can have a negative effect on people’s health and low ventilation may result in an increase in allergic diseases. Quantification of air change rate is complicated, since it is affected by a number of parameters, of which the one of the most variable is the air-wind flow. This study aims to determination and comparison of values of the air change rate in two methods - by quantifying of aerodynamic coefficient Cp = Cpe - Cpi – so called aerodynamic quantification of the building and the methodology based on experimental measurements of carbon dioxide in the selected reference room in apartment building.


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